Processing columns commonly contain a bed of granular material such, for example, as ion exchange resin, through which a liquid is passed to treat either the liquid or the granular material. In order to distribute the liquid uniformly to the bed, a plurality of interconnected apertured conduits are ordinarily arranged across either the top or bottom of the bed on the upstream side thereof. In like manner the liquid which has passed through the bed may be collected by a similar arrangement of apertured tubes on the downstream side of the bed. In many processes the same tubes are used both for purposes of distribution and collection in in different steps of the process.
In order to prevent the granular material from exiting the processing vessel along with the liquid, the distributor-collector conduits are ordinarily covered with a filter medium such, for example, as a tube of fine mesh woven cloth. In order to maintain the integrity of the seals between the ends of the cloth tube and the underlying apertured conduit, metal clamps which tightly compress the end portions of the cloth tube against resilient rings disposed on the conduits have generally been used.
Inasmuch as many processes involve the treatment of liquids which are corrosive to most metals or which themselves become contaminated by most metals, it is desirable to provide a distributor-collector system which is made entirely of plastic or other inert material and yet maintains the integrity of the seals between the filter cloth and the underlying conduit. Also, it is important to provide a distributor-collector system which may be easily disassembled for maintenance and replacement of the fine mesh cloth tube when necessary.
Many distributor-collector systems are custom designed for particular applications. Accordingly, maintaining an inventory of such parts for replacement or repair is necessarily costly. It is therefore, desirable to provide a distributor-collector system utilizing only standard parts but adaptable to use in various custom engineered applications.
In the copending Schmidt application referred to above, there is disclosed a distributor-collector assembly having no metallic parts and which employs filter cartridges which may be assembled in the field from a few basic parts. Since the apertures in the cartridges are preferably arranged in a row at the bottom of the cartridge, a problem with the said system has been the difficulty in properly orienting the cartridges in the distributor-collector assembly. Moreover the cartridge design disclosed in the said application requires that the filter cartridges be assembled at the time the distributor-collector assembly is being fabricated inasmuch as one part of each cartridge assembly is also a part of the manifold.